1. Field of Invention
The present invention relates generally to access doors and, more particularly, to a method and apparatus for constructing an access door and frame from a single sheet of material.
So-called access doors for providing access to an attic space, crawl space, or storage space through a wall or ceiling are well known to those skilled in the art. Typically, the access door is mounted between joists and/or frame members in the building being framed by a finish molding about the peripheral edges of the door.
In many installations, the finish molding is mitered at the corner junctures of the finish molding resulting in a joint that has to be filled during the finishing process. This joint typically cracks open and separates due to settling and other stresses to the building structure requiring maintenance and painting.
Thus, the present invention has been developed to provide a combined access door and peripheral frame constructed from a single piece of material to eliminate the corner joints thereof.
2. Description of Related Prior Art
U.S. Pat. No. 5,327,682 to Claudia P. Holtz discloses an access panel having a removable door and recessed hinge. The panel is made of a molded plastic such as styrene polymer. The door is press-fit and is held in the frame by grooves in the frame which align with the resilient protuberances on the door panel. A hidden hinge, which allows the door to be hinged or removed from the frame, is provided. Although the peripheral frame does not require corner joints, the door and frame are not constructed of a single sheet of material in the manner of the present invention.
U.S. Pat. No. 4,738,054 to James C. Muth et al. discloses an access door assembly for a ceiling including a frame adapted to be attached to supports of the ceiling and mounted in a generally horizontal position, and a door which fits within and has one edge hingedly connected to the frame. However, this door assembly requires several structural members to construct the frame and also requires relatively complex hardware and moving parts to operate the door assembly.
U.S. Pat. No. 1,925,635 to Cyril J. Hartley discloses a manhole cover and frame being of triangular form and having pivots situated adjacent to two of its corners so that it can be easily raised from its frame about these pivots by the operator lifting the cover at or near its third corner. However, this invention differs significantly from the single piece construction of the present invention.
U.S. Pat. No. 4,619,086 to Hiromitsu Naka discloses a ceiling construction for buildings having a plurality of hinged main beams disposed in a predetermined space relationship; a plurality of flanged cross beams connected to the main beams in a predetermined space relationship at right angles to the main beams so as to form a ceiling framework; a ceiling wall mounted on the ceiling framework so as to form an access opening in a predetermined position; and an access door with a plurality of mounting devices for mounting the door within the access opening. However, this ceiling construction is a complex structure having numerous components required to frame the access opening wherein a separately constructed door is mounted.
U.S. Pat. No. 3,598,686 to John E. Clark discloses a wall panel for a building structure comprising of fiberglass outer shell and a frame assembly positioned within the shell. The frame assembly is fiberglassed into the shell and the frame assembly is welded to the supporting structure of the building. However, this invention requires a more complex construction than the present intention having a significant number of panel components in its assembly.
Finally, U.S. Pat. No. Des. 374,486 to Quinton M. Guin discloses an ornamental design for a combined door and frame for a crawl space opening as shown and described.